In March 2014 he was finally found guilty of 33 charges – including two counts of murder – and jailed for a minimum of 35 years.

Philip said he was “one of the lucky ones”.

The shocking events at Stepping Hill feature in the TV series Crimes That Shook Britain.

Bosses at Stepping Hill have revised security since the attacks but admit they can’t guarantee it won’t happen again.

Stockport NHS Trust’s medical director Dr James Catania said: “Fundamentally you can’t legislate against any person who wants to commit a criminal act and hospitals, by their own nature, are very open places.”

A statement from the hospital said: “Whilst no hospital’s systems and processes can offer a complete guarantee against the actions of a determined criminal, additional measures are now in place which go beyond standard practice.”